Ciro Santilli @cirosantilli 37

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AI training robot dataset Updated 2025-07-16

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3D rigid body dynamics simulator Updated 2025-07-16

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3D rigid body dynamics Updated 2025-07-16

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3D file format viewer Updated 2025-07-16

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askubuntu.com/questions/1319549/is-there-any-simple-3d-viewer-application

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2006 Nobel Prize in Physics Updated 2025-07-16

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Hidden Answers Updated 2025-07-16

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www.reddit.com/r/onions/comments/sfquss/hidden_answers_is_back/ gives pbqttnffb5sh6ckgnz4f5by55w25gd6tuw5f5qcctmnyk62eyhgx6rad.onion which is Dead Janary 2024

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1978 Nobel Prize in Physics Updated 2025-07-16

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tcpdump Updated 2025-07-16

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To test it, let's get two computers on the same local area network, e.g. connected to Wi-Fi on the same home modem router.

On computer B:

find computer IP with the ip CLI tool. Suppose it is 192.168.1.102
then run Ciro's nc HTTP test server

On computer A, run on terminal 1:

sudo tcpdump ip src 192.168.1.102 or dst 192.168.1.102

Then on terminal 2 make a test request:

curl 192.168.1.102:8000

Output on terminal 1:

17:14:22.017001 IP ciro-p14s.55798 > 192.168.1.102.8000: Flags [S], seq 2563867413, win 64240, options [mss 1460,sackOK,TS val 303966323 ecr 0,nop,wscale 7], length 0
17:14:22.073957 IP 192.168.1.102.8000 > ciro-p14s.55798: Flags [S.], seq 1371418143, ack 2563867414, win 65160, options [mss 1460,sackOK,TS val 171832817 ecr 303966323,nop,wscale 7], length 0
17:14:22.074002 IP ciro-p14s.55798 > 192.168.1.102.8000: Flags [.], ack 1, win 502, options [nop,nop,TS val 303966380 ecr 171832817], length 0
17:14:22.074195 IP ciro-p14s.55798 > 192.168.1.102.8000: Flags [P.], seq 1:82, ack 1, win 502, options [nop,nop,TS val 303966380 ecr 171832817], length 81
17:14:22.076710 IP 192.168.1.102.8000 > ciro-p14s.55798: Flags [P.], seq 1:80, ack 1, win 510, options [nop,nop,TS val 171832821 ecr 303966380], length 79
17:14:22.076710 IP 192.168.1.102.8000 > ciro-p14s.55798: Flags [.], ack 82, win 510, options [nop,nop,TS val 171832821 ecr 303966380], length 0
17:14:22.076727 IP ciro-p14s.55798 > 192.168.1.102.8000: Flags [.], ack 80, win 502, options [nop,nop,TS val 303966383 ecr 171832821], length 0
17:14:22.077006 IP ciro-p14s.55798 > 192.168.1.102.8000: Flags [F.], seq 82, ack 80, win 502, options [nop,nop,TS val 303966383 ecr 171832821], length 0
17:14:22.077564 IP 192.168.1.102.8000 > ciro-p14s.55798: Flags [F.], seq 80, ack 82, win 510, options [nop,nop,TS val 171832821 ecr 303966380], length 0
17:14:22.077578 IP ciro-p14s.55798 > 192.168.1.102.8000: Flags [.], ack 81, win 502, options [nop,nop,TS val 303966384 ecr 171832821], length 0
17:14:22.079429 IP 192.168.1.102.8000 > ciro-p14s.55798: Flags [.], ack 83, win 510, options [nop,nop,TS val 171832824 ecr 303966383], length 0

TODO understand them all! Possibly correlate with Wireshark, or use -A option to dump content.

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SPARQL tutorial Updated 2025-07-16

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In this tutorial, we will use the Jena SPARQL hello world as a starting point. Tested on Apache Jena 4.10.0.

Basic query on rdf/vcard.ttl RDF Turtle data to find the person with full name "John Smith":

sparql --data=rdf/vcard.ttl --query=<( printf '%s\n' 'SELECT ?x WHERE { ?x <http://www.w3.org/2001/vcard-rdf/3.0#FN> "John Smith" }')

Output:

---------------------------------
| x                             |
=================================
| <http://somewhere/JohnSmith/> |
---------------------------------

To avoid writing http://www.w3.org/2001/vcard-rdf/3.0# a billion times as queries grow larger, we can use the PREFIX syntax:

sparql --data=rdf/vcard.ttl --query=<( printf '%s\n' '
PREFIX vc: <http://www.w3.org/2001/vcard-rdf/3.0#>
SELECT ?x
WHERE { ?x vc:FN "John Smith" }
')

Output:

---------------------------------
| x                             |
=================================
| <http://somewhere/JohnSmith/> |
---------------------------------

Bibliography:

UniProt contains some amazing examples runnable on their servers: sparql.uniprot.org/.well-known/sparql-examples/

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ROCm Updated 2025-07-16

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Official hello world: github.com/ROCm/HIP-Examples/blob/ff8123937c8851d86b1edfbad9f032462c48aa05/HIP-Examples-Applications/HelloWorld/HelloWorld.cpp

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Crystal radio Updated 2025-07-16

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This was the first generation of commercially successful radios.

It uses a crystal detector as its diode, which is a crucial element of the radio, thus its name.

They were superseded by transistor radios, which were much more reliable, portable and could amplify the signal received.

Video 1.

How a Crystal radio Works by RimstarOrg

. Source.

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ROCm on Ubuntu Updated 2025-07-16

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Tested on Ubuntu 23.10 with P14s:

sudo apt install hipcc
git clone https://github.com/ROCm/HIP-Examples
cd HIP-Examples/HIP-Examples-Applications/HelloWorld
make

TODO fails with:

/bin/hipcc -g   -c -o HelloWorld.o HelloWorld.cpp
clang: error: cannot find ROCm device library for gfx1103; provide its path via '--rocm-path' or '--rocm-device-lib-path', or pass '-nogpulib' to build without ROCm device library
make: *** [<builtin>: HelloWorld.o] Error 1

Generic Ubuntu install bibliograpy:

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Crate image with given text in ImageMagick Updated 2025-07-16

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Digits 0 to 9, white on black background:

for i in `seq 0 9`; do convert -size 512x512 xc:black -pointsize 500 -gravity center -fill white -draw "text 0,0 \"$i\"" $i.png; done

Bibliography:

stackoverflow.com/questions/67012057/how-to-generate-an-image-with-a-number-in-it

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Bitcoin inscription bibliography Updated 2025-07-16

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en.wikipedia.org/wiki/History_of_bitcoin#Arbitrary_blockchain_content

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ccTLD Updated 2025-07-16

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Oxford Physics student course notes Updated 2025-07-16

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liziyan1117.com/page/:
These are my own solutions to selected problem sets and past papers of the Oxford MPhys course (Years 1-3) and the MMathPhys course from the years 2014 to 2018
All question PDFs are uploaded to that site. Solutions are scanned from paper notebooks.
From LinkedIn:
I identify myself as a black lesbian, who is trapped inside an Asian straight man's body.
pjcc.physics.ox.ac.uk/resources/notes | www.scribd.com/document/654784089/CP3-Notes-Toby-Adkins# are lectures by Toby Adkins is pointed to from Oxford Physics Joint Consultative Committee. But they are closed, i.e. require you to be in the oxford network, though not necessarily with an Oxford login. As of 2023, he was doing a postdoc: www.physics.ox.ac.uk/our-people/adkins in fusion energy.

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Infrastructure as a service Updated 2025-07-16

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You SSH into a an OS like Ubuntu and do whatever you want from there. E.g. Amazon EC2.

The OS is usually virualized, and you get only a certain share of the CPU by default.

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OurBigBook feature Updated 2025-07-16

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Peter Todd's hash collision puzzles Updated 2025-07-16

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As mentioned at the prize was claimed at 8d31992805518fd62daa3bdd2a5c4fd2cd3054c9b3dca1d78055e9528cff6adc (2017-02-23) which spends several inputs with the same unlock script that presents two different constantants that have the same SHA-1:

printf 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 | xxd -r -p | sha1sum
printf 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 | xxd -r -p | sha1sum

both giving

f92d74e3874587aaf443d1db961d4e26dde13e9c

It was claimed on the same day that Google disclosed the collision: security.googleblog.com/2017/02/announcing-first-sha1-collision.html

Both of these are PDF prefixes, so they start with the PDF file signature, but are not fully viewable PDFs on their own.

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Opera Magistris Updated 2025-07-16

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www.sciences.ch/

v3 LaTeX source code: github.com/OperaMagistris/Opera_Magistris_English_v3

Very unfortunate license "public domain license" with a "non religious" clause, whatever the fuck that is, which completely defeats the point of a public domain declaration:

The source code and text is under Public License and therefore can be used, translated and distributed at free will.
It is only banned to use the text and content for religious propaganda.

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